The invention relates to a device for the control of additional quantities of gases into the induction manifold or tube of an internal combustion engine downstream of a throttle valve, the construction being such that the throttle valve is arranged to control entry of gases into the air stream. In this type of known device an exhaust gas return line opens vertically into an induction tube of an internal combustion engine so that the opening plane in the center of the induction tube lies approximately at the height of a throttle valve shaft. The opening of the exhaust gas return line is associated with the throttle valve in such a manner that the portion of the throttle valve that lies downstream of the throttle valve shaft completely closes the opening of the exhaust gas return line when the throttle valve is completely opened. In order to maintain a sealed closing of the exhaust gas return line, however, there needs to be a precise association of the throttle valve and the opening plane of the exhaust gas return line.